Irish social workers must "stop immediately" the practice of acting in conjunction with their UK counterparts in seeking the return to Britain of children at the centre of care proceedings without the parents' knowledge of that application, the Court of Appeal has said.

If it does not stop, social workers could face contempt of court proceedings, Mr Justice Gerard Hogan said. He also expressed the "deepest misgivings" about the conduct of Irish and English social workers in one such case.

It was a practice which had grown up in recent times whereby UK social workers travel to Ireland for to arrange the return of children by applying to the courts here without notice to the parents "thus depriving them of any opportunity" to challenge the proceedings.

The judge said it was difficult "to avoid the impression that the child care system provided for under the Child Care Act 1991 is being circumvented for this purpose".

The practice of removing children without serving notice of the court proceedings on the parents is "a wholly unlawful one".

He was commenting during an appeal over three children, all under six, who were brought by their British parents to Ireland on September, with the youngest having born only two days previously.

The two oldest children had been the subject of interim care orders in the UK and, three days after they left, all three were made wards of court by the English High Court.

Concerns had previously been expressed by the social services unit of their local county council about the standards of hygiene within the home, the parental capacity to manage the children, domestic violence in previous relationships and parental substance abuse, Mr Justice Hogan said.

The same day as the wardship orders were obtained in the UK, the English social services contacted their counterparts here in the Child and Family Agency (CFA) to say they had also obtained the requisite orders that the children be returned.

The CFA, on September 11, made an unannounced visit to the home of the family here and, Mr Justice Hogan said, it was important to note that "nothing of concern" was found.

The District Court here granted interim care orders, with the consent of the parents, to the CFA which meant the children were placed in foster care. The parents were told by the CFA the UK social services would apply to have the English court order that they be returned by means of making an application for an enforcement order to the High Court here, without notice to the parents.

On September 21, the High Court, on an ex-parte application by the English county council, made that order and the three children were handed over by the CFA to English social workers at the Rosslare ferryport and brought back to the UK. The parents were told afterwards as the English social workers had expressly requested their CFA counterparts not to contact them because they were considered a flight risk.

Mr Justice Hogan said it was "impossible not to have the deepest misgivings about the conduct of two public institutions, one British (the English county council) and one Irish (the CFA) in this entire matter".

The parents appealed the ex-parte order to the Irish High Court but were ruled out of time by two days. As a result, they then went to the three-judge Court of Appeal.

Mr Justice Hogan said the English county council, which did not participate in the Appeal Court hearing for financial reasons, said it did not intend to return the children "irrespective of the outcome of the appeal to this court".

The English council also made it clear it intended going ahead with adoption proceedings in the UK for the three children.

Mr Justice Hogan found the enforcement of the English court order concerning the return of the children amounted to a "wrongful circumvention" of Article 11 of the Brussels II bis Regulation which deals with the competent authorities in member EU states to deliver judgment in wrongful removal of children from their country of habitual residence cases. It also circumvented "the entire" Hague Convention which deals with the same matters, he said.

As a result, the judge said, the court had decided to refer to the Court of Justice of the EU (CJEU) the question of whether a return, in circumstances such, as this amounted to a circumvention of EU regulations and the Hague Convention, or an abuse of rights or law.